1. Field of the Invention
The instant invention is generally related to climbing aids for rock climbers. More particularly, this invention is related to mechanical devices that link climbing aids together.
2. Description of the Prior Art
Climbers utilize rope, slings and a variety of mechanical devices as climbing aids to assist and protect their movement over rock. The climbing aids serve as a means to anchor the climber to the rock for the purpose of either preventing or arresting a fall.
A carabiner is a mechanical device used to link rope, slings and other climbing aids together. A carabiner is essentially a device used, for example, to attach a climber's body harness to the climbing rope. It is also used to link the climbing rope to anchors placed in or over the rock.
A typical carabiner is palm sized, and either an oblong, oval or “D” shaped ring of a lightweight, high strength material, usually a heat-treated aluminum alloy. One side of the carabiner has a hinged arm that serves as an inward opening gate. The gate is spring loaded to remain normally closed. The normally closed, inward opening gate facilitates insertion of climbing aids such as rope, but impedes inadvertent removal. Objects are released from the carabiner after manually pushing open the gate.
The closing force is provided by a stout compression spring that is housed within the carabiner gate. The spring axis is offset from the pivot pin so that the spring force is directed to close the gate. A link is employed to transfer the spring force to the carabiner body at an appropriate distance from the pivot pin.
The opening end of the gate incorporates an interlocking mechanism that engages the carabiner body when the gate is closed. The interlocking mechanism is typically a transverse pin that mates with a hooked notch in the carabiner body. Another popular configuration includes a keyed arrangement that mates with the carabiner body. These interlocking arrangements allow a closed gate to carry part of the load imposed on the carabiner. Consequently, the carabiner is significantly stronger when the gate is closed. The ultimate strength of a carabiner with the gate open is typically 65% lower than with the gate closed.
During a climb and especially in the event of a fall, the climber's safety is dependent on the security of numerous carabiner links. Consequently, it is imperative that every carabiner in the chain be able to withstand not only the weight of the climber but also the inertial forces generated when the rope arrests a fall.
As the climber progresses upward, the carabiners in a protective chain of climbing aids often rub against the rock. Occasionally, a carabiner gate will catch on a rock or other object, or the rope itself, and may be pushed or pulled open without the climber's knowledge. A carabiner can slap against the rock during a fall causing inertial loads that overcome the closing force of the spring and momentarily open the gate. Also, a rope moving rapidly through a carabiner during a fall can cause the carabiner body to vibrate sufficiently to shake the gate open.
Whenever the gate is opened, even momentarily, there is significant risk that a rope or other attached climbing aid will be inadvertently released. Furthermore, if a sudden load is applied to the carabiner at the instant that the gate is open, the ultimate strength of the carabiner will be significantly compromised and possibly fail. Such occurrences are well known and are considered a significant problem by the climbing community. Consequently, climbers pay careful attention to the placement and orientation of carabiners in order to minimize the chance of an inadvertent opening of the gate.
Climbers often use two carabiners joined by a short length of looped webbing, a combination called a quickdraw. One of the quickdraw carabiners is clipped to an anchor placed in or on the rock. The other quickdraw carabiner is clipped to the climber's rope. The quickdraw allows the rope to pull toward the centerline between staggered anchors thereby providing a less resistive path from the belay point to the climber.
A quickdraw requires the use of two carabiners to attach a rope to a single anchor. Assembling quickdraws with smaller, lightweight carabiners minimizes the weight and bulk penalty of using two carabiners.
A properly placed quickdraw may have the additional benefit of reducing the chance of an inadvertent opening of the gate. Unfortunately this is often not the case. For example, if the rope is incorrectly threaded through the carabiner, a moving rope can twist the carabiner and expose the gate to a sideward opening force. If the rope is pulled across or around the gate, the gate can be inadvertently opened
A climber must be very careful when placing and clipping into a quickdraw. The dangling carabiner (the carabiner that will be clipped to the climbers rope) must be oriented so that its gate is away from the rock face. When the rope is clipped in, it must run along the spine of the carabiner, not across the gate.
Many carabiners have a bent gate to facilitate clipping the rope. The gate is bent inward slightly which serves to guide the rope to the opening end. The dangling carabiner of quickdraw configurations customarily has a bent gate.
Placing the rope into the quickdraw's dangling carabiner requires skill and dexterity. Usually the climber is hanging on to the rock surface with one hand, and has only one hand free to clip in the rope. Depending on which hand is free, and the location and orientation of the carabiner relative to the climber, a variation of two techniques is typically used: 1. The carabiner is stabilized with the middle finger, and the rope is clipped in with the thumb and index fingers; or 2. Stabilize the carabiner with the thumb, and clip the rope using the index and middle fingers. No matter the technique used, the carabiner gate must open easily and without hesitation.
There are situations where the risk of an inadvertent opening of the gate is unacceptable, For example, the carabiner used to attach the climbing rope to the climber's body harness must never open inadvertently. Similarly, the carabiner used to attach a belay device to the climber's harness must never open inadvertently. Consequently, harness attachments and the like require greater security, for example, two parallel carabiners or a single carabiner with a locking gate.
Greater security can be obtained by using two carabiners side-by-side with the gates opening in opposite directions. However, extra carabiners solely for the purpose of parallel placement are undesirable because they add considerably to the weight and bulk that the climber must carry.
To avoid the need for side-by-side carabiners, various mechanical means have been developed to directly lock the carabiner gate closed. For example, a popular locking configuration incorporates a sleeve that is threaded, nut like, to the gate. The sleeve can be screwed along the length of the gate, either toward the hinge, or toward the opening end. The sleeve is screwed into the locking position after the rope or other climbing aids have been clipped into the carabiner. In one configuration the gate is locked closed by screwing the sleeve until it crosses the opening end of the gate and jams against the adjacent body of the carabiner. In an alternate configuration the gate is immobilized when the sleeve is screwed over the hinge. Locking or unlocking a carabiner with a threaded sleeve is not instantaneous, that is, it takes time to thread the sleeve from the unlocked position to the locked position and the reverse.
Unfortunately, threaded locking sleeves undesirably add bulk and weight to the carabiner. Threaded locking sleeves are also inherently troublesome. The threads can become clogged with dirt or ice. The sleeve can inadvertently screw out of the locked position when the carabiner rubs across the rock. Furthermore, the gate and threaded cleave mechanism require precise machining and assembly alignment, both of which add to manufacturing cost.
Other solutions of the prior art include gates equipped with spring loaded sliding and/or rotary sleeves. Sliding and/or rotary sleeves function similarly to threaded sleeves, and are often designed to lock automatically and nearly instantaneously when the gate closes. Sliding and rotary sleeves share the same problems as threaded sleeves, and are especially costly to manufacture.
The increased bulk, weight and cost of the prior art limits the number of locking carabiners that a climber carries during a climb or is willing to buy. Consequently, there may be situations during a climb when the climber is compelled to use a non-locking carabiner although a locking type would be preferable or safer.
Although the security of quickdraw applications would benefit from the use of locking carabiners, quickdraws do not incorporate locking carabiners because state-of-the-art locking carabiners are relatively heavy and bulky. The need to be able to easily and instantly clip a rope using only one hand make spring-loaded auto-locking gates especially inappropriate for quick draw use. Furthermore, locking sleeves can only be mounted on straight gates, whereas most quickdraw configurations utilize a bent gate carabiner.
The instant invention is a carabiner incorporating a mechanism that securely and reliably locks the gate closed with the flick of a finger. The inventive locking mechanism is contained inside the gate; therefore it does not add bulk or weight to the carabiner and is less susceptible to jamming by contamination. The inventive locking mechanism has a snap action toggle that maintains the gate unlocked until the climber desires to lock it. The instant invention is ideally suited for quickdraw applications because there is not a weight or bulk penalty, it works with bent gates, and the gate will remain unlocked for clipping a rope, but can be easily and quickly locked after the rope is in place.